loki/pkg/storage/chunk/cache/groupcache_test.go

package cache

import (
	"context"
	"testing"

	"github.com/go-kit/log"

	"github.com/grafana/dskit/ring"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGroupCache(t *testing.T) {
	gc, err := setupGroupCache()
	require.Nil(t, err)

	c := gc.NewGroup("test-group", &GroupConfig{}, "test")
	defer c.Stop()

	keys := []string{"key1", "key2", "key3"}
	bufs := [][]byte{[]byte("data1"), []byte("data2"), []byte("data3")}
	miss := []string{"miss1", "miss2"}

	err = c.Store(context.Background(), keys, bufs)
	require.NoError(t, err)

	// test hits
	found, data, missed, _ := c.Fetch(context.Background(), keys)

	require.Len(t, found, len(keys))
	require.Len(t, missed, 0)
	for i := 0; i < len(keys); i++ {
		require.Equal(t, keys[i], found[i])
		require.Equal(t, bufs[i], data[i])
	}

	// test misses
	found, _, missed, _ = c.Fetch(context.Background(), miss)

	require.Len(t, found, 0)
	require.Len(t, missed, len(miss))
	for i := 0; i < len(miss); i++ {
		require.Equal(t, miss[i], missed[i])
	}

	// passing empty GroupConfig should use global `CapacityMB`.(which is 1MB).
	c1 := gc.NewGroup("test-group1", &GroupConfig{}, "test1")
	defer c.Stop()

	assert.Equal(t, c1.(*group).cacheBytes, int64(1*1e6))

	// pass explicitly capacity per group should take preference.
	c2 := gc.NewGroup("test-group2", &GroupConfig{CapacityMB: 6}, "test2")
	defer c.Stop()

	assert.Equal(t, c2.(*group).cacheBytes, int64(6*1e6))

}

func setupGroupCache() (*GroupCache, error) {
	return NewGroupCache(&mockRingManager{}, GroupCacheConfig{
		Enabled:    true,
		CapacityMB: 1,
	}, log.NewNopLogger(), nil)
}

type mockRingManager struct{}

func (rm *mockRingManager) Addr() string {
	return "http://localhost:1234"
}

func (rm *mockRingManager) Ring() ring.ReadRing {
	return &mockRing{}
}

type mockRing struct {
	ring.ReadRing
}

func (r *mockRing) GetAllHealthy(op ring.Operation) (ring.ReplicationSet, error) {
	return ring.ReplicationSet{Instances: []ring.InstanceDesc{
		{
			Addr: "http://localhost:1234",
		},
	}}, nil
}